Stock drenching instrument



Dec. 4, 1934. G. P. KAUZAL 1,982,9934 STCK DRENCHING INSTRUMENT Filed June 5, `1954 Patented Dec. 4, 1934 1,982,999 y s'roorl` DRENCHING INSTRUMENT Gabriel Peter Kauzal, Sydney, `New South Wales, Australia,- assignor-to Ject-InLimited, Sydney, New South Wales, Australia, a company of New South Wales, Australia y Application ,lune 5., 1934, serial No. 729,142 In Australia'June 6, 1933 2 claims. (o1. `12m-223) This invention relates to instruments usedby veterinariansgand stockmen for drenching farm stock. v

The inventionrelates in particular to drenchl ing syringes of the known kind in which the instrument is provided with a pistol gripflstock, the plunger is actuated by a trigger, the barrel is fitted with inlet and delivery check valves, and the drench liquid is supplied by gravity to `l() the inlet valve through a flexible pipe from a knapsack or from a reservoir vessel.

The present invention consists ink piston stroke regulating means which enable the user to vary the dosage with great facility and rapidity, and

it ,further consists the. detail of the trigger mechanism.

In practice, drenching of farm stock is usually carried out by stockmen under conditions which make it impracticable to use syringes which are gu fitted with dose varying means which necessitate anything more than mere simple movement of a regulator member. Any adjustment device is without practical utility unless it can be manipulated almost instantly and with certainty. While the stockman is grasping the animal as it isracing through a crush, the usual screw stops on the plunger operating rod such as are iitted on surgeons syringes cannot be manipulated with the necessary rapidity and correct- 39v ness; such close observation is necessary and so much time is required for the adjusting operation in the use of such vsyringes that it cannot be performed satisfactorily in the conditions above mentioned.

The adjustment device which is the essential feature of the present invention requires only the turning of a knob so as to click it past latching checks, each click representing a known variation in the length of stroke of the plunger and consequently in the volume of the dose. The instrument is self-charging as the trigger is spring retracted and brings back the plunger to admit the dose, and whether the adjustment be set for full dose or for only a partial dose the trigger is pulled at each stroke for the full movement which is permitted to it by the dosage adjustment device. y

The structural features of this instrument are illustrated in the accompanying drawing, in which:-

Fig. l is a longitudinal sectional elevation; and

Figs. 2 and 3 are fragmentary longitudinal sections through the stock and barrel breech and explanatory of the features of the regulator byywhich the volume of the dose to be administered may be varied. y y

The butt of the cylinder 20` is screwed into the stock 2l and is locked therein by a grub screw 22. The pistol grip `handle 23 is integral 60 with the stock 21. The trigger lever 24 is held normally in the retired position shown by a helical tensioned spring 25, and vits upper end 26 is v forked and the fork arms are pivotally engaged to the back ends of a pair of links 27. The 6 5 forward ends of these links are integral with or connected to a bridge 29 which is pivotally connected across the hollow'back'of the plunger 3. The plunger vis reciprocated forwardly in the cylinder 28r by a full'movement on the trigger 70 lever 24, and it is reciprocated backward by the action of the spring 25.

The range of the plunger movement in the cylinder controls the volume of the dose of drench. This range is regulated by manually rotating a milled edge dial knob 31 at the back of the stock, a latch spring 32 being provided for engaging notches in the knob edge to hold it in adjusted position. Instead of a leaf spring latch, a spring plunger latch or a spring ball latch may be fitted. The dial knob 31 is fixed on the back end of a spindle 33 which passes freely through a forked sleeve 34, and carries a pin key 37 near its inner end. The forked sleeve 34 is screwed into the stock and locked by a grub screw 36. The pin key 3'? works ina helical slot 40 in a tubular sleeve 38. The sleeve 38 is slidable along the spindle 33 but is incapable of rotation thereon because it is embraced'between the jaws 35 of the forked sleeve 34 which are slidable between the mating slots 39 in the side of it. When the knob 3l is rotated in the positive direction the pin key 37 is moved along the helical slot 40 and causes the sleeve 38 to advance towards the plunger; conversely when the knob 31 is rotated in the negative direction it causes the sleeve 38 to retire from the plunger. The rearward position is determined by the setting of the dial knob, as the bridge 29 is checked against the front end of the helically slotted sleeve 38; the forward limit of the plunger position is determined by its contact with the front end of the cylinder; a

final fine adjustment may be made at the factory with a screw 53 and lock nut 54 (Fig. 3).

The retiring spring 25 tilts the trigger 24 to the reset position; in that movement the trigger i tail 26 draws the plunger to the full back position as it is linked (2'7) to the plunger by the side rods 2'7.

The piston is preferably made in non-corrosive plug 46 which is screwed into a cross pocket in'` the nozzle butt preferably integral with the cylinder barrel. Drench liquid passes-from the pipe 44 through the valve 45 and ports 47 in the plug 46 into the cylinder When V`the plunger is drawn.

back upon finger pressure ,onA the triggerglever being released; the plunger is thus brought back to a position predetermined by the setting of the dial knob 31. Finger pressure applied to the trigger' lever forces the plunger forward, "ex-A pelling the measured dose through the ports 47 and 48 past the spring loaded discharge valve 49 and through the nozzle 52. Retraction of any portion of the expelled liquid is preventedvby the discharge valve 49. That valve is housed in a u tubular longitudinal pocket 51 in the butt of the nozzle 52. The knob spindle 33 is checked against endwise movement in forked sleeve 34 by the shoulder 41 and boss 42 on the dial knob.

When the knob 31 is rotated, the key pin 37 on its spindle advances or retires the helically slotted sleeve 38 according to the direction of the adjusting movement and the back stroke position of the plunger is checked accordingly, the spindle 33 being prevented from drawing it back beyond the ,check position determined by the adjustment.

^ When the sleeve 38 is drawn full back, the plunger is permitted a full length movementl Conversely, in any other adjusted position, its throw is more or less restricted and a correspondingly reduced dose is supplied for delivery.

What I claim as my invention and desire to secure by Letters Patent isz- 1. In a gravity fed stock drenching syringe having a pistol grip, trigger action plunger driving means, inlet and delivery check valves at the fore end of the cylinder, and a nozzle, a dose volume regulating device consisting of a rotatable spindle in alignment with the barrel butt With a knobr xed tomsaid spindle externally of the stock and engageable by a dialling check, and a non-rotatable sleeve floating on said spindle and helically grooved to coact with a lateral key pin on said spindle to elect endwise movement of said sleeve in relation to the plunger, and thereby operative for limiting the throw ofthe plunger in correspondence with the adjustment of said knob. f f I Y f 2. In a drenching syringe according to claim 1, a trigger with pull back spring linked to a cross head pin on a plunger back, a helically slotted tubular check member behind the plunger splined longitudinally toa sleeve fixed in the back of the stock, and a spindle checked against endwise movement but rotatable within said sleeve by means of a dialling knob located behind the stock, said spindle fitted with a key pin engaged in the helical slot so as when the knob is adjusted by turning 4it the plunger throw is checked in correspondence with said knob adjustment.

GABRIEL PETER KAUZAL.

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